Reed relay construction

ABSTRACT

A reed relay, the essential novelty of which resides in the provision of a novel and unique bobbin assembly, said assembly comprising a bobbin constructed of electrically insulating material and having a hollow, elongated central core with an outwardly extending circular flange at one end thereof and an enlarged cylindrical body portion at the opposite end, said enlarged body portion having a pair of spaced circumferentially extending recesses therein, each of said recesses having a further recessed portion extending through said enlarged body into communication with the exterior of said core, and a pair of spaced leads extending axially from outside said bobbin through said enlarged body into said recesses, said leads having inner portions bent outwardly with respect to said enlarged body, said outwardly bent portions being diametrically opposed from each other and each being adapted to receive one of the ends of a drive coil that is wound around said central core.

United States Patent [191 Abrams REED RELAY CONSTRUCTION [75] Inventor: Ralph Abrams, Warwick, R1.

[52] US. Cl 335/151; 335/154 [51] Int. Cl? HOlH 51/28 [58] Field of Search 335/151, 152, 153, 154

[56] References Cited UNITED STATES PATENTS 11/1965 Bengtsson 335/154 7/1972 Rovnyak 335/154 Primary ExaminerHarold Broome Attorney, Agent, or Firm-Salter & Michaelson [57] ABSTRACT A reed relay, the essential novelty of which resides in Dec. 23, 1975 the provision of a novel and unique bobbin assembly, said assembly comprising a bobbin constructed of electrically insulating material and having a hollow, elongated central core with an outwardly extending circular flange at one end thereof and an enlarged cylindrical body portion at the opposite end, said enlarged body portion having a pair of spaced circumferentially extending recesses therein, each of said recesses having a further recessed portion extending through said enlarged body into communication with the exterior of said core, and a pair of spaced leads extending axially from outside said bobbin through said enlarged body into said recesses, said leads having inner portions bent outwardly with respect to said enlarged body, said outwardly bent portions being diametrically opposed from each other and each being adapted to receive one of the ends of a drive coil that is wound around said central core.

6 Claims, 8 Drawing Figures US. Patent Dec. 23, 1975 3,928,829

REED RELAY CONSTRUCTION BACKGROUND AND SUMMARY OF THE INVENTION The present invention relates generally to a reed relay construction and is more particularly concerned with the provision of a novel and improved bobbin assembly utilized therein.

The usual reed relay comprises a bobbin having a hollow central core, said core being adapted to receive therein an encapsulated reed switch, the leads of which extend outwardly through opposite ends of the bobbin. A drive coil is wound around the outside of the bobbin core with the opposite ends of the drive coil connected to suitable electrical leads whereby energization of the coil by the passage of a current therethrough electromagnetically operates the reed switch. Examples of reed relays of this general type are shown in Becker et al. US. Pat. No. 3,456,216 dated July 15, l969,'and Campbell US. Pat. No. 3,701,960 dated Oct. 31, 1972.

One of the problems that has been found to exist in reed relays of this type is the time and labor required to connect the opposite ends of the drive coil to their respective leads while at the same time maintaining proper electrical insulation between said leads and the non-insulated ends of the coil to which the leads are connected. Since these assemblies are usually quite small in size, extreme care must be taken to insure proper spacing or insulation between said terminals, and it is frequently necessary to wrap insulating tapes around the outside of the coil to insure proper insulation between the coil ends and their respective leads. As stated, this has proven to be a laborious assembly operation and one which adds significantly to the overall cost of the relay.

It is therefore a primary object of the present invention to provide a unique and specially constructed bobbin which greatly facilitates and expedites the connection of the coil ends to their respective leads while at the same time automatically providing and maintaining proper insulation between said terminals. This objective is accomplished by providing a bobbin constructed of an electrically insulating material, such as nylon, polypropylene, or any other suitable plastic material, having an elongate hollow central core with a circular flange at one end and an enlarged cylindrical body portion at its opposite end. The enlarged body portion is provided with a pair of spaced, circumferentially extending recesses, each of which has a further recessed portion communicating with the exterior of the core. A pair of spaced leads extend axially from outside the bobbin through said enlarged body portion with one of the leads going into one of the recesses, and the other lead going into the other recess. The innermost portions of the leads are then bent outwardly from their respective recesses whereby the pair of leads extend radially outward from the bobbin in diametrically opposed relation. Thus, it will be seen that the enlarged body portion of the bobbin receives the two leads and maintains them insulated with respect to each other. After the drive coil has been wound around the core of the bobbin, one end of the coil is extended through the adjacent communicating recess and electrically connected to one of the leads while the other end of the coil is passed through the other communicating recess and is electrically connected to the other lead. This can easily be accomplished without any danger of shorting taking place between the coil ends. The outwardly extending lead portions are then bent downwardly so that they are received within their respective circumferentially extending recess whereupon the bobbin and coil assembly is completed. A conventional reed switch is then slidably inserted within the hollow central core, one end of the bobbin being open to receive the switch, and the other end being closed with the exception of a small opening for receiving the lead from the reed switch. The assembly may then be completed by sliding the bobbin and reed switch into a cylindrical case or shell which acts as a cover for the relay.

Other objects, features and advantages of the invention will become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.

DESCRIPTION OF THE DRAWINGS In the drawings which illustrate the best mode presently contemplated for carrying out the present invention:

FIG. 1 is a perspective view of the bobbin and lead assembly which forms an important part of the present invention;

FIG. 2 is a perspective view showing the assembly of FIG. 1 after a drive coil has been wound therearound and electrically connected;

FIG. 3 is an exploded elevational view, partially in section, showing the wound bobbin, the reed switch, and the outer shell prior to assembly with each other;

FIG. 4 is a sectional view of the bobbin and lead assembly shown in FIG. 1;

FIG. 5 is an side elevational view of the completely assembled relay;

FIG. 6 is a section taken on line 6-6 of FIG. 5;

FIG. 7 is a left-end view of the assembly of FIG. 5; and

FIG. 8 is a sectional view similar to FIG. 6 showing a slightly modified form of the present invention wherein two reed switches are utilized.

DESCRIPTION OF THE INVENTION Referring now to the drawings, and more particularly to FIGS. 1 and 4, there is shown generally at 10 a bobbin' and lead assembly, the bobbin comprising a hollow central core 12 with a marginal outwardly extending circular flange 14 at one end thereof. At the opposite end of the core 12, there is provided an enlarged cylindrical body portion 16, it being understood that the outer diameter of portion 16 is substantially the same as the outer diameter of flange 14. The body portion 16 is provided with a pair of identical, oppositely disposed and circumferentially extending recesses 18, each of which has a further recessed portion 20 extending perpendicularly from one end thereof, said recessed portions communicating with the exterior of core 12, the bottom surfaces of said recessed portions 20 being substantially flush with the outer surface of said core. As will be noted, flange 14 has a central opening 22 communicating with the interior of hollow core 12, the diameter of the opening 22 being substantially the same as the inner diameter of core 12. A pair of oppositely disposed small openings 24 are provided in flange 14 for purposes which will hereinafter become apparently. Also, the core l2is provided with an elongated opening 26 extending therethrough, said opening being located adjacent cylindrical body portion 16, again for reasons hereinafter to be made apparent.

The above-described bobbin is constructed of an electrically insulating material, such as nylon, polypropylene, or any other suitable plastic material. plastic being preferred since it has been found economically feasible to injection mold said bobbin. In practicc..a glass-filled nylon has been used in the manufacture of said bobbin with good results.

A pair of spaced wire leads 28, 30 extend in an axial direction from outside of the bobbin through enlarged cylindrical portion 16. More specifically. the leads 28 and 30 each extend into one of the recesses 18 in alignment with the further recessed portions 20. The inner ends of the leads 28, 30 are bent outwardly in diametrically opposite directions, as shown at 28a and 300. It will thus be seen that the leads 28 and 30 and their bent ends 28a and 300 are electrically insulated from each other by virtue of their spaced positions in cylindrical portion I6.The opening 26 has been provided in core 12 to permit and facilitate the insertion of automatic tools for use in connection with the automatic assembly of leads 28 and 30 with the bobbin and for automatically effecting the outward bending of the inner ends of said leads.

The bobbin assembly is adapted to receive a drive coil 32 normally comprising a very fine insulated copper wire that is wound around the exterior of core 12, as shown most clearly in FIGS. 2 and 3. The coil 32 is preferably wound as evenly and symmetrically possible around core 12 to provide for even dissipation of heat throughout its surface, and it will be understood that the voltage rating and number of turns of coil 32 is such as to electromagnetically actuate reed switch 34 which is subsequently positioned within the interior of hollow core 12. The opposite ends ofcoil 32 are shown in FIG. 3 at 32a and 32b, said ends each extending through one of the recessed portions 20, after which the ends 32a and 32b are connected to lead portions 280 and a such as by being soldered thereto, or by any other suitable means so as to effect an electrical junction between said wires and said leads. After this electrical connection has been made, the lead portions 28a and 300 are then bent inwardly so that they each are positioned within their respective recess 18, as illustrated most clearly in FIG. 2. It is important to note that the lead portions 28a and 30a are bent downwardly in the same direction as that in which coil 32 is wound. This provides for an automatic strain relief when the leads 28a and 300 are bent downwardly, whereby there is less likelihood of the coil ends tearing away from their respective leads when the latter are bent downwardly.

As previously stated, reed switch 34, which is of conventional construction, is positioned within the interior of hollow core 12. More specifically, reed switch 34 comprises an encapsulated switch 36 having leads 38, 40 extending from opposite ends thereof. The switch 34 is adapted to be inserted through the opening 22 in flange 14 whereby it is freely received within the hollow interior of core 12. As will be seen most clearly in FIG. 4, the end of enlarged cylindrical portion 16 is substantially closed with the exception of a small central aperture 42, the function of which is to receive lead 38 of switch 34 so that said lead may extend therethrough. After the reed switch 34 has been positioned within the bobbin assembly 10, an outer shell or cover 44, preferablyof molded plastic, although it could be of metallic construction, is provided for receiving the bobbin assembly. More specifically, the shell or cover 44 comprises a hollow cylinder closed at one end as at 46 and open at its opposite end 48. A pair of downwardly extending legs 50 extend tangentially from opposite sides of shell 44, shown most clearly in FIG. 6. End wall 46 is provided with a small central aperture 52 and with a pair of diametrically opposed lugs 54 extending inwardly from the inner surface of wall 46. The inner diameter of shell 44 is such as to snugly receive the assembly 10, with switch 34 positioned therein, through open end 48, it being understood that lead 40 of reed switch 34 will pass through the opening 52 in wall 46, whereby the entire bobbin and reed switch assembly is housed within shell 44 with the exception of the outwardly extending leads. In order to secure the cover 44 over the bobbin and reed switch assembly, the outer edge of enlarged cylindrical portion 16, which is positioned at open end 48, is epoxied to surrounding shell 44. The three outwardly extending leads located adjacent the end 48 of shell 44, namely leads 28, 30 and 38, are then bent downwardly, as is lead 40 extending from the opposite end of shell 44, as shown most clearly in FIGS. 5, 6 and 7.

It will be noted that when the bobbin and reed switch assembly is slid into shell 44, the outer surface of flange 14 will engage the inner surface of wall 46. By properly orienting the bobbin within shell 44, it will be seen that lugs 44 will engage within openings 22, in which position the bobbin and reed switch assembly will be properly aligned with shell 44 so that leads 28, 30 and 38 are horizontally aligned in generally parallel relation with the bottom of shell 44, it being understood that the depending legs 50 define the bottom ofsaid shell. Thus, the lugs 54 in openings 22 actually function as cooperating detents for properly positioning the bobbin assembly within outer shell or cover 44.

It will be understood that the interior of hollow bobbin core 12 is of sufficient size to receive different-size reed switches; and, if desired, the bobbin and core may be configured, as illustrated in FIG. 8, so as to receive a pair of side-by-side reed switches therein. It will be understood that the assembly shown in FIG. 8 is identical in all respects to that of FIGS. 1 through 7 with the single exception that a pair of reed switches are received within the bobbin.

While there is shown and described herein certain specific structure embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described except insofar as indicated by the scope of the appended claims.

What is claimed is:

l. A reed relay bobbin constructed of electrically insulating material and comprising a hollow elongate central core, an outwardly extending marginal flange at one end of said core, an enlarged cylindrical body at the other end thereof, a pair of spaced circumferentially extending recesses in said body located intermediate the ends thereof, each of said recesses having a further recessed portion at one end thereof extending through said body and communicating with the exterior of said core, and a pair of spaced leads extending axially from outside said bobbin through said body into said recesses, one lead extending into one of said recesses and the other lead into the other of said recesses, the inner ends of said leads being bent so .as to be positioned in said eircumferentially extending recesses, one end of said bobbin having an opening of substantially the same size as the interior of said core, and the other end of said bobbin being substantially closed but having an opening therethrough of substantially smaller size than the interior of said core.

2. In combination with the bobbin of claim 1, an electrically conductive coil wound around said core, one end of said coil extending through one of said further recessed portions and making electrical connection with one of said lead inner portions, and the other end of said coil extending through the other of said further recessed portions and making electrical contact with the other of said lead inner portions.

3. The combination of claim 2 further comprising an encapsulated reed switch having wire leads extending from opposite ends of the capsule, said reed switch being positioned within said hollow bobbin core with one of said wire leads extending outwardly through the 6 open end ofsaid bobbin and the other wire lead extending through said smaller opening at the substantially closed end of said bobbinv 4. The combination of claim 3 further comprising an outer cylindrical shell snugly receiving said bobbin,

their respective coil end is wound. l l 

1. A reed relay bobbin constructed of electrically insulating material and comprising a hollow elongate central core, an outwardly extending marginal flange at one end of said core, an enlarged cylindrical body at the other end thereof, a pair of spaced circumferentially extending recesses in said body located intermediate the ends thereof, each of said recesses having a further recessed portion at one end thereof extending through said body and communicating with the exterior of said core, and a pair of spaced leads extending axially from outside said bobbin through said body into said recesses, one lead extending into one of said recesses and the other lead into the other of said recesses, the inner ends of said leads being bent so as to be positioned in said circumferentially extending recesses, one end of said bobbin having an opening of substantially the same size as the interior of said core, and the other end of said bobbin being substantially closed but having an opening therethrough of substantially smaller size than the interior of said core.
 2. In combination with the bobbin of claim 1, an electrically conductive coil wound around said core, one end of said coil extending through one of said further recessed portions and making electrical connection with one of said lead inner portions, and the other end of said coil extending through the other of said further recessed portions and makiNg electrical contact with the other of said lead inner portions.
 3. The combination of claim 2 further comprising an encapsulated reed switch having wire leads extending from opposite ends of the capsule, said reed switch being positioned within said hollow bobbin core with one of said wire leads extending outwardly through the open end of said bobbin and the other wire lead extending through said smaller opening at the substantially closed end of said bobbin.
 4. The combination of claim 3 further comprising an outer cylindrical shell snugly receiving said bobbin therein, said shell having one open end positioned adjacent the substantially closed end of said bobbin, and a closed end positioned adjacent said bobbin open end, said closed shell end having an opening therethrough of substantially the same size and in general alignment with said smaller opening in said bobbin closed end.
 5. In the combination of claim 5, said shell and said bobbin having cooperating detent means for insuring proper orientation therebetween.
 6. In the combination of claim 2, said leads being bent in the same direction as the direction in which their respective coil end is wound. 